The defiant Ivory Coast president, Laurent Gbagbo, is facing a financial crisis that could see the military turn on him and force him from power, his opponents have claimed.

International banks have frozen his accounts, many businesses are refusing to take government cheques, and it is not clear how long civil servants will be able to go on drawing their salaries.

Gbagbo remained immovable today as the latest delegation of African leaders flew into Abidjan to offer him amnesty if he agrees to step down in the wake of November's disputed elections. But aides to Gbagbo's rival, Alassane Ouattara, believe the economic noose tightening around his neck could succeed where the threat of military action has failed.

"Gbagbo won't be able to rule the country, to borrow money for the Ivorian state or to pay the salaries of civil servants and the military," said Patrick Achi, a former infrastructure minister under Gbagbo who now serves as a Ouattara spokesman. "The question is, how long will he be able to stay in power before he is financially asphyxiated?"

Last week Ivory Coast missed a coupon payment on its $2.3bn Eurobond, but a month grace period means it is not yet in default. The World Bank has frozen aid of more than $800m, and postponed an arduously negotiated debt relief programme.

The Central Bank of West African States has given Ouattara signature rights and said it longer recognises Gbagbo as president, a decision that effectively meant he lost access to state accounts at the bank.

This is already having an impact, a source at the presidency said. "A lot of businesses are refusing to take cheques from the presidency because they are worried they will bounce. Gbagbo is running out of money."

The youth minister, Charles Blé Goudé, a staunch Gbagbo ally known for his belligerent speeches, last week accused France of withholding the salaries of civil servants, and called on Ivorians to boycott French banks and transfer their savings to local, Ivorian-owned banks.

Blé Goudé even made the unlikely claim that Gbagbo's government was considering pulling out of the regional CFA franc. "Ghana, Nigeria and Guinea have their own currencies, and they are still functioning," he said. "For our economic independence, our country will soon have its own currency."

The government's wage bill is estimated at about $170m a month. It was not clear how many civil servants had been able to withdraw money from their bank account last month. A teacher in Abidjan said he had received half his usual monthly salary, while a retired civil servant said he had been "happily surprised" to see his pension paid in full.

Gbagbo has always made it a point to pay the security forces first. The wage bill for the military has steadily increased since he took office in 2000: the national police force has nearly doubled in size.

In addition, he shored up support among the army by recruiting thousands of youth from his native Bet region. As a result, the country's national security forces are believed to have reached about 44,000, with army chief general Philippe Mangou alone reportedly taking in as much as €40,000 a month.

He still has other sources of income: he retains control of the lucrative oil and cocoa sectors. Officially, Ivory Coast produces 60,000 barrels of crude a day, but real output may be double that. According to the IMF, revenues from oil sales already exceed income from cocoa bean exports, which bring in an estimated $1bn a year.

Critics say Gbagbo has made handsome personal profits by turning a blind eye to embezzlement in the cocoa industry, rewarding his friends with oil concessions, and giving the notoriously corrupt Lebanese business community illicit tax exemptions. In 2006 the World Bank complained that a large share of public expenditures "was executed outside regular budget procedures" – a byword for corruption.

Some Gbagbo supporters optimistically believe China will come to the rescue. Like other African leaders, Gbagbo has boasted of his friendship with China following the arrival of major Chinese telecoms and construction companies in Ivory Coast.

The presidents of Benin, Sierra Leone and Cape Verde, along with Kenyan prime minister Raila Odinga, travelled to Abidjan today for talks with Gbagbo. But earlier a spokesman for Gbagbo, Ohoupa Sessegnon, said a deal would be rejected. "It's not about Laurent Gbagbo seeking some sort of offer," he told the BBC. "It's about Laurent Gbagbo having won the elections in the Cote D'Ivoire. Now it appears that the opposition supported by the French and their allies do not want to accept that."